A Location Service (LCS) in a mobile communication network is to obtain location information of a target UE through location technologies. Wherein, the target UE is a located equipment terminal in the mobile communication network, and the location information can be information of geographical latitude and longitude information or location information for local streets. The location information obtained by the mobile communication network can be provided for the target UE and be used for locating the target UE itself; or be provided for the communication network itself for area-based charging or operation maintenance; or be provided for other application clients, which request the location information of the target UE, such as organizations and individuals, for value-added services. Therefore, the LCS is widely applied in emergency rescues, vehicle navigations and intelligent traffic systems, work dispatches and workgroup management, mobile information inquiries, network performance enhancements and so on. In the 3rd Generation Partnership Project (3GPP), the LCS specification together with the function modules, structures, status descriptions, and message processes for implementing the LCS is illustrated thereof.
FIG. 1 is a schematic diagram illustrating logic structure of the LCS. As shown in FIG. 1, a requester 101 requests a network 102 with the LCS system to provide location information of a target UE 103, the network 102 with the LCS system checks the validity of the requester 101 to determine whether the target UE 103 allows the requester 101 to request for its location information; if the requester 101 passes the authentication of the network 102 with the LCS system, the network 102 with the LCS system will locate the target UE 103 and then provide the requester 101 with the location information of the target UE 103; otherwise, the network 102 with the LCS system will reject the location information request toward the target UE 103 from the requester 101.
In an LCS system, function logic entities for implementing location service include: a Gateway Mobile Location Center (GMLC), a Home Location Register/Home Subscriber Server (HLR/HSS), a Central Network (CN) and a Radio Access Network (RAN). The GMLC may further include a Requesting GMLC (R-GMLC), a Home GMLC (H-GMLC) and a Visited GMLC (V-GMLC). The R-GMLC is the GMLC for receiving the location information request to the target UE initiated by the requester; the H-GMLC is the GMLC which the target UC belongs to; the V-GMLC is the GMLC in the network with the LCS system that the target UE visits, namely the GMLC that the target UE is currently located. The R-GMLC, the H-GMLC and the V-GMLC can be in a same physical entity, or be in different physical entities.
At present, 3GPP Specification defines the process of a Mobile Original Location Request (MO-LR). The generic procedure of MO-LR includes: the target UE request the LCS system for the location information of the target UE itself; the LCS system locates the target UE before sending the location estimate to the target UE; furthermore, on request of the target UE, the LCS system can provide an external requester with the location estimate of the target UE, herein the requester refers to a client that can process the location information of the target UE, such as an LCS client or an application client, rather than a literal requester that requests for the location information of the target UE.
FIG. 2 is a flowchart illustrating the process of the MO-LR in the prior art. As shown in FIG. 2, the process of the MO-LR includes:
Step 201: a target UE sends a service request to the CN through the RAN to request a wireless signaling connection with the network with the LCS system, and then the network with the LCS system may initiate a procedure of authenticating and ciphering the target UE; if the target UE passes the authentication of the network with the LCS system, the network with the LCS system continues to execute step 202; otherwise, the network with the LCS system rejects the service request for the wireless signaling connection initiated by the target UE and terminate the current process of the MO-LR.
Step 202˜step 204: the target UE sends a MO-LR Location Services Invoke to the CN through the RAN and requests the CN to locate the target UE, herein the LCS MO-LR Location Services Invoke can further carry information of an external requester and request LCS system to provide the corresponding requester with the obtained location information of the target UE. After receiving the LCS MO-LR Location Services Invoke, the CN can determine whether the target UE has subscribed to the MO-LR service according to the stored information; if the target UE has not subscribed to the MO-LR service, the CN will return to the target UE an LCS MO-LR Location Services Invoke response carrying the error reason and reject the MO-LR Location Services Invoke initiated by the target UE; if the target UE has subscribed to the MO-LR service, the CN will send to the RAN a Location Request carrying an identifier of the target UE, the RAN will locate the target UE after receiving the Location Request.
Step 205: after finishing locating the target UE, the RAN returns a target UE location report to the CN, if the RAN successfully locates the target UE, i.e. obtains the location information of the target UE, the target UE location report will carry the location information of the target UE, if the target UE demands that the LCS system provides a corresponding requester with the obtained location information of the target UE, step 206 to step 210 will be further executed after the CN receives the target UE location report; otherwise, the CN directly returns an LCS MO-LR response carrying the location information of the target UE to the target UE through the RAN. If the RAN fails in obtaining the location information of the target UE, the target UE location report will carry the error reason and the CN will return a LCS MO-LR response carrying the error reason to the target UE through the RAN.
Step 206˜step 207: the CN sends to a specified GMLC a target UE location report carrying a requester identifier and the location information of the target UE. After receiving the target UE location report, GMLC sends a target UE location information report carrying the location information of the target UE to the corresponding requester according to the requester identifier.
Step 208˜step 209: after receiving the target UE location information report, the requester determines whether it's able to process the location information of the target UE; if the requester is able to process the location information of the target UE, the requester returns a target UE location information report response carrying a success mark to the GMLC; otherwise, the requester returns a target UE location information report response carrying a failure mark to the GMLC. After receiving the target UE location information report response, according to the content carried in the target UE location information report response, the GMLC returns a target UE location report response that carries corresponding content to the CN. In other words, if the GMLC receives the target UE location information report response with a success mark, the GMLC will return a target UE location report response with a success mark to the CN; if the GMLC receives the target UE location information report response with the error reason, the GMLC will return a target UE location report response with the error reason to the CN.
Step 210: after receiving the target UE location report response, according to the content carried in the target UE location report response, the CN returns an LCS MO-LR response carrying the corresponding content to the target UE. In other words, if the CN receives the target UE location report response with a success mark, the CN will return an LCS MO-LR response carrying the location information to the target UE and notify the target UE that the CN has provided the requester with the location information; if the CN receives the target UE location report response with the error reason, the CN will return an LCS MO-LR response carrying the location information to the target UE, and return the error reason to the target UE to notify the target UE that the CN has provided the requester with the location information, but the corresponding requester is unable to correctly process the location information of the target UE.
It can be seen from the aforesaid process of the MO-LR Location Services Invoke defined by 3GPP specification that, when the target UE requests the network with the LCS system for the location information of the target UE, charging information is generated in the current CN of the target UE. But in practical network operation, the CN is taken as a fundamental entity for a bearer process in the network and there are a number of CNs. It is infeasible to place a specific service charging point in the CN, otherwise the process of the CN will be too much related to the service, and when the service is changed, e.g. the service is updated, the corresponding CN needs to be updated as well. Moreover, there are a large number of CN nodes in the network, if a certain service is changed, the whole network will be affected, which is not favorable to the service's development and popularization.
In addition, when the target UE requests the network with the LCS system for the location information of the target UE and demands the LCS system to provide an external requester with the location information of the target UE, the CN in the LCS system will provide the external requester with the location information of the target UE through GMLC after receiving the location information of the target UE. The aforesaid GMLC can be specified by the target UE in the LCS MO-LR Location Services Invoke, or be randomly allocated by the CN according to GMLC address information stored in the CN. In practical network operation, when the address information of the GMLC is specified by the target UE, if the current located CN of the target UE and the GMLC specified by the target UE do not belong to the same network, the current located CN of the target UE may not be able to access the GMLC; when the address information of the GMLC is allocated by the CN, herein according to the stored GMLC address information, the CN can allocate a GMLC that the CN can directly access, but the GMLC may not be able to access the specified requester, i.e. the GMLC that can directly access the requester is not the GMLC allocated by the CN. Thus, the existing MO-LR process can not provide the requester specified by the target UE with the location information of the target UE, which greatly limits the development of the MO-LR service.